1. Field of the Invention
The invention relates to a liquid crystal display (LCD) device, and more particularly to a light-emitting element circuit disposed in a flexible printed circuit (hereinafter is referred to as FPC) and a LCD device comprising the flexible printed circuit.
2. Description of the Related Art
FIG. 1 is a cross-section illustrating a typical light emitting diode (LED) FPC. As shown in FIG. 1, a light-emitting element circuit comprises LEDs 110, 112, 114, and 116. The light-emitting element circuit is arranged in an FPC 100. The LEDs 110 and 112 are connected in series by the line 120 and are arranged in one side of the FPC 100. The LEDs 114 and 116 are connected in series by the line 122 and are arranged in an opposing side of the FPC 100. The line 120 is divided into a first part 120b (shown as a solid line) and a second part 120a (shown as a dashed line). The line 122 is divided into a first part 122b (shown in the solid line) and a second part 122a (shown in the dashed line). A positive current I2 flows through the LED 110 and the LED 112 sequentially via the lines 120a and outputs through the lines 120b. A positive current i1 flows through the LED 114 and the LED 116 sequentially via the lines 122a and outputs through the lines 122b. The inner impedances of LEDs 110, 112, 114, and 116 are different. The impedance difference is about 10˜20 ohms. Thus, in the structure, the current i2 is not equal to the current I1. If the difference between the inner impedance of each LED is larger, the difference in value between the current I2 and the current I1 increases. This difference in impedance diminishes the quality of light brightness by the device comprising the FPC 100, thereby reducing the uniformity. Additionally, positive and negative power lines are arranged alternately, thus production of the FPC is complex.